Microplastic pollution in Caspian kutum (Rutilus frisii kutum) on southern shores of the Caspian Sea

Microplastics exists in marine habitats all over the world, and laboratory studies show that, this substance can be swallowed up by fish and transmitted through human consumption of fish. However, data on its abundance in lakes are limited. The purpose of this study is to determine the amount of micro-plastic accumulation on Caspian kutum as a seafood. This study was carried out on 51 whitefish collected during the fishing season (February to March) 2017 at six stations (Gomishan, Babolsar, Mahmoudabad, Tonekabon, Chamkhaleh, Bandar Anzali) on the southern shores of the Caspian Sea. The results showed that in the gastrointestinal tract, 66.6% of the fish were micro plastics. On average, each fish was swallowed by 1.47 pieces of micro plastics the most of these micro plastics were fibers (38.75%), then fragments (42.31%), films (30%) and beads (11.42%). These data show that there is a significant amount of micro plastics contamination in the Caspian Sea fish. The consumption of this fish may transfer micro plastic to humans. The results of this study were compared with reports from other parts of the world indicating that more study in the Caspian Sea should be conducted.